摘要
针对在隧道等高地温环境中混凝土强度损失大、耐久性差等问题,通过试验研究了添加钢纤维、聚丙烯纤维和玻化微珠的一种复合混凝土在经历热养护后的力学性能,揭示了抗压强度、抗拉强度和破坏特征随养护温度的变化规律。由均匀化理论推导了考虑热-力关系的复合混凝土单轴压缩强度公式。结果表明:相较于无材料添加的普通混凝土,复合混凝土具有更高的抗压强度和抗拉强度,在热养护后强度损失率较小;复合混凝土在破坏后“裂而不散”,具有较高的残余强度;纤维等夹杂材料有助于提高混凝土高温后的强度及耐久性;基于均匀化理论建立的混凝土强度模型与试验结果吻合较好。研究结果可为高地温隧道衬砌结构的优化设计提供依据。
To tackle the problems of strength loss and poor durability of concrete in high geothermal tunnel,we examined the mechanical properties of composite concretes undergone thermal curing mixed with steel fiber,polypropylene fiber and vitrified microspheres,hence revealing the variation of compressive strength,tensile strength and failure characteristics of composite concretes with curing temperature.Furthermore,we deduced the formula of uniaxial compression strength of composite concretes considering the thermal-force relationship based on the homogenization theory.Results unveiled that the composite concretes are of higher compressive strength and tensile strength compared with ordinary concrete with no such mixtures,and have smaller strength loss after thermal curing.Failed sample is cracked but not separated,implying higher residual strength.The inclusion materials in the composite concretes attribute to the strength and durability after high temperature curing.The concrete strength model based on the homogenization theory fits well with the experimental results.The research findings offer theoretical basis for the design and evaluation of lining structures in high geothermal tunnel.
作者
魏涛
陈国庆
徐鹏
WEI Tao;CHEN Guo-qing;XU Peng(State Key Laboratory of Geohazard Prevention and Geoenvironment Protection,Chengdu University of Technology,Chengdu 610059,China;School of Environmental and Civil Engineering,Chengdu University of Technology,Chengdu 610059,China)
出处
《长江科学院院报》
CSCD
北大核心
2020年第12期157-164,共8页
Journal of Changjiang River Scientific Research Institute
基金
国家自然科学基金项目(41572283)
国家创新研究群体科学基金项目(41521002)。
关键词
复合混凝土
热养护
高地温环境
力学性能
破坏特征
均匀化理论
热应力
composite concrete
thermal curing
high geothermal environment
mechanical property
failure characteristics
homogenization theory
thermal stress
